1. Field of the Invention
This invention relates to an automatic film developing machine for developing an exposed photographic film.
2. Description of the Prior Art
Conventional automatic developing machines for photographic films have such a structure that a photographic film is caused to pass through a developer-containing tank so as to develop the photographic film. A number of rollers are arranged in pairs in the tank. These rollers are rotated so that a film to be developed is pinched between the roller in each pair and is hence conveyed through the tank. Its development has been completed when the film is fed out of the tank.
In such a conventional developing machine, the film is transported through the developer in the small tank. It is hence necessary to have the film pass through the tank while bending same. The conventional developing machines are therefore accompanied by drawbacks that many rollers are required and the overall size of the developing machine becomes large.
With a view toward improving the drawbacks of such conventional developing machines, a developing machine has been proposed as disclosed in Japanese Utility Model Publication No. 20115/1985. Some of its structural features will next be described with reference to FIG. 1.
FIG. 1 is a cross-sectional side view of the automatic film developing machine proposed in the above publication. Numerals 1,2 indicate film feed rollers provided in a pair and letter a indicates their nip. Numeral 3,4 indicate film feed rollers provided in a pair in opposition to the film feed rollers 1,2. The nip of the film feed rollers 3,4 is also designated by a. The line connecting both nips a,a (i.e., the line shown in phantom in FIG. 1) is substantially horizontal. There are also illustrated a catch pan 5 provided underneath the paired film feed rollers 1,2,3,4, a bottom wall 5a of the catch pan 5, and a raised central portion 5a' of the bottom wall 5a of the catch pan 5. Numeral 5b indicates both side walls of the catch pan 5. However, one of the side walls 5b is only shown in FIG. 1. A space 6 is formed by the film feed rollers 1,2,3,4, catch pan 5 and side walls 5b. Designated at numerals 7,8 are blades provided respectively in elastic contact with the rollers 2,4 in order to avoid fluid leakage from the space 6. Numeral 9 indicates an overflow outlet formed through the side wall 5b. Designated at numeral 10 is a return pipe for collecting the developer overflowed to the outside from the space 6 and then recycling same to an unillustrated reservoir.
When the developer is pumped up from the unillustrated reservoir and is then charged into the space 6, the level of the developer rises in the space 6 and eventually reaches the height of the overflow outlet 9. When the developer is fed further, the developer overflows through the overflow outlet 9 to the outside of the space 6. The thus-overflowed developer is then recycled to the unillustrated reservoir through a return pipe 10. As a result, the level of the developer is always maintained at the height of the overflow outlet 9. As shown in FIG. 1, the overflow outlet 9 is formed at a height higher than the line which connects the nips a,a to each other. When the film feed rollers 1,2,3,4 are rotated in a direction indicated by arrows and a film to be developed is fed between the film feed rollers 1,2 on the left-hand side as viewed in the drawing, the film passes from the film feed rollers 1,2 and then through the developer in the space, and is thereafter fed out of the space 6 while being pinched between the film feed rollers 3,4. As a result, the film can be developed surely without being bent. Moreover, the opposing two pairs of rollers are only required so that the developing machine can itself be constructed in a small size.
In the above-described automatic film developing machine, the overflow outlet 9 is formed through the side wall 5b. The extra portion of the developer is therefore discharged continuously onto the outer surface of the side wall 5b. The outer surface is hence blemished. Moreover, the catch for receiving the developer discharged onto the outer wall must extend out from the side wall 5b, leading to another problem that the overall structure becomes large.